Portable blower/vac

ABSTRACT

An improved convertible electric blower/vac. The blower/vac includes an improved air inlet cover with an adjustable choke member. The air inlet cover also includes a pressure ring for increasing the efficiency of the blower/vac impeller when the unit is operated in the blower mode. The blower/vac also includes a blower tube and a vacuum bag collar, each with resilient tabs that engage receptacles on the blower/vac to retain the blower tube and vacuum bag collar on the unit. The housing outlet of the blower/vac includes guides that interact with longitudinal ribs on the blower tube and the vacuum bag collar to reduce unwanted rotational deflection of the blower tube and vacuum bag collar when either is engaged on the housing outlet. The blower/vac includes an improved vacuum tube for use of the blower/vac in the vacuum mode.

This application is a divisional application of Ser. No. 08/434,728filed on May 4, 1995 and entitled Portable Blower/Vacuum HandleArrangement, now U.S. Pat. No. 5,560,078. This invention pertains toelectric blower/vacs. Specifically, this invention pertains to electricblower/vacs which are readily convertible between the blower mode andthe vacuum mode.

TECHNICAL FIELD Background of the Invention

Convertible blower/vac units are in common use by homeowners andprofessionals for the removal of debris from yards and driveways. Aconvertible blower/vac is a device which can be used as a blower orwhich can be converted to operate as a vacuum.

In blower operation, typical blower/vac units provide a sweeping actioncreated by the production of a fast moving stream of air from a rotatingimpeller within a housing. A removable exhaust or blower tube generallycarries the air stream from the housing of the unit so that a nozzle atthe outlet of the blower tube can be near the ground while the unit isbeing held by the operator. The nozzle at the end of the blower tube isgenerally smaller than the outlet port on the housing of the unit, thuscausing a higher velocity air stream at the nozzle and allowing forgreater precision and force in blowing debris across a surface.

Conversion from the blower mode to the vacuum typically requiresremoving the blower tube from the housing outlet and placing a debriscatching vacuum bag on the outlet. An air inlet cover is removed fromthe housing inlet and a vacuum tube is placed over the inlet. In vacuumoperation, the hand held device draws air and debris through the vacuumtube. Debris is reduced as it is drawn up through the impeller. Thedebris is then propelled into the vacuum bag for disposal.

Modern units are typically hand-held and, therefore, are made oflightweight materials and utilize lightweight power sources. The twomost common power sources for the units are electric and gasolinemotors.

One prior art portable blower/vac is disclosed in U.S. Pat. No.5,222,275 issued to Baker et al. on Jun. 29, 1993. Baker discloses aconvertible electric blower/vac with a removable air inlet cover andmeans for attaching a blower tube, a vacuum bag, and a vacuum tube tothe housing.

U.S. Pat. No. 4,644,606 issued to Luerken et al. on Feb. 24, 1987discloses a convertible gas engine powered blower/vac with a vacuum tubewith a generally circular cross-section. Luerken et al. also discloses ablower tube with a generally circular cross-section. Luerken et al. alsodiscloses an air inlet cover with no means for adjusting the inlet areaalthough the air volume and speed through the blower/vac can be adjustedby varying the throttle setting of the gas engine which drives theimpeller.

U.S. Pat. No. 4,694,528 issued to Comer et al. on Sep. 22, 1987discloses a convertible electric blower/vac with a removable air inletcover including means for adjusting the air inlet area of the cover. Themeans for adjusting the inlet area includes a series of axially (inrelation to the fan motor shaft) disposed air inlet openings and aconcentrically mounted air choke with a series of axially disposedspokes. When the choke is rotated such that the choke spokes cover theair inlet openings, the air inlet area is reduced and the resultantairflow through the blower/vac is reduced. When the choke is rotatedsuch that the choke spokes move away from and expose the air inletopenings, the inlet area is increased and the resultant air flow throughthe blower/vac is increased. Comer et al. also discloses a blower tubeand a vacuum tube of a generally circular cross-section. The vacuum tubeis attached over the air inlet of the housing by means of a bayonet-typefitting while the blower tube is attached to the housing outlet by meansof a shallow, fine pitch screw thread. The air inlet cover includes apressure ring for increasing the efficiency of the impeller when theunit is operated in the blower mode. The pressure ring is integral withthe member forming the air inlet openings but is a separate componentfrom the air inlet cover proper.

U.S. Pat. No. 4,413,371 issued to Tuggle et al. on Nov. 8, 1983discloses a power blower with a blower tube that tapers from a generallycircular cross-section at its upstream end to a generally rectangularcross-section at its downstream end.

U.S. Pat. No. 4,325,163 issued to Mattson et al. on Apr. 20, 1982discloses a convertible electric blower/vac with a removable air inletcover. The air inlet cover does not include any means for adjusting theair inlet area of the cover. Mattson et al. also discloses a blower tubewith a generally circular cross-section wherein the blower tube isjoined to the housing outlet by means of a friction fit. The vacuum tubeis also connected to the housing by means of a friction fit while thevacuum bag is attached the housing outlet by means of a strap whichsecures the bag inlet around the housing outlet.

U.S. Pat. No. 4,945,604 issued to Miner et al. on Aug. 7, 1990 disclosesa portable blower with a blower tube having a circular cross-section atits upstream end and a generally rectangular cross-section at itsdownstream end. The blower tube is removably connected to the blower bymeans of a bayonet-type fitting arrangement. U.S. Pat. No. 2,586,145issued to Breuer et al. on Feb. 19, 1952 discloses a convertibleelectric blower/vac with a removable nozzle for use in the blower mode.The nozzle is removably connected to the downstream end of the blowertube by means of sliding engagement collar and pin connector system. Aresilient finger cooperates with the sliding engagement collar to retainthe removable nozzle on the blower tube. The removable nozzle hasgenerally circular cross-section at its upstream end and a generallyrectangular cross-section at its downstream end. The outlet portion ofthe nozzle is disposed at an angle of approximately 60° from thelongitudinal axis of the neck or upstream portion.

U.S. Pat. No. 5,035,588 issued to Sadler et al. on Jul. 30, 1991discloses a convertible gasoline powered blower/vac with means forresiliently and frictionally engaging a blower tube or a vacuum outlettube into the housing outlet. The blower tube has a generally circularcross-section at its upstream end and a generally rectangularcross-section at its downstream end.

U.S. Pat. No. 4,553,284 discloses a vacuum cleaner universal nozzle madefrom a resilient material which is manually deformable such that theinlet opening and configuration can be altered by the operator to suitoperating conditions.

U.S. Pat. No. 2,068,496 issued to Linghammar on May 21, 1936 discloses avacuum tube with a generally cylindrical upstream portion and a funnelshaped downstream portion. The funnel shaped downstream portion is madeof a flexible material and can thus be deformed to conform to irregularshape surfaces. Linghammar also discloses a series of longitudinal ribsrunning along the inner surface of the funnel shaped downstream portion.These ribs prevent the flexible funnel shaped downstream portion fromcollapsing due to the partial vacuum created by the fan.

Toro parts catalog, form #3316-626, 1993 copyright to The Toro Companydiscloses a convertible electric blower/vacuum with a removable airinlet cover. The air inlet cover includes means for adjusting the airinlet area. The means for adjusting the air inlet area includes a seriesof axially (in relation to the fan motor shaft) disposed air inletopenings and a concentrically mounted air choke with a series of axiallydisposed spokes. When the choke is rotated such that the choke spokescover the air inlet openings, the air inlet area is reduced and theresultant airflow through the blower/vac is reduced. When the choke isrotated such that the choke spokes move away from and expose the airinlet openings, the inlet area is increased and the resultant airflowthrough the blower/vac is increased. The convertible electric blower/vacalso includes a pressure ring that is integral with the member formingthe air inlet openings, but the pressure ring is a separate componentfrom the air inlet cover proper.

Paramount operator's manual #534-886570-8, 1993 copyright to ParamountDivision of WCI Outdoor Products, Inc. discloses a convertible electricblower/vac with a removable air inlet cover that includes means foradjusting the inlet area through the air inlet cover. The means foradjusting the inlet area includes a series of radially disposed openingson the air inlet cover. A pivoting choke member is fastened to the airinlet cover and includes a series of radially disposed spokes. When thechoke is rotated such that the spokes obstruct the radially disposedopenings on the cover, airflow through the blower/vac is reduced. Whenthe choke is rotated such that the spokes move away from the coveropenings, then airflow through the blower/vac is increased. TheParamount unit does not include axially disposed choke spokes or inletcover openings, nor does it include a pressure ring.

The Paramount PB-100 power blower manufactured in 1990 and shown in theParamount parts list #534-500069 dated Dec. 12, 1990, discloses anelectric blower including an air inlet cover with an adjustable chokemember. The air inlet cover and the choke member each include a seriesof radially disposed spokes and air inlet openings as well as a seriesof axially disposed spokes and air inlet openings. The choke member ismounted concentrically on the air inlet cover and can be rotated suchthat in one position the spokes of the choke member cover the air inletopenings of the air inlet cover. In the other position, the spokes ofthe choke member are rotated away from the air inlet openings, thusexposing the openings and allowing air to pass through the air inletcover. The air inlet cover of the Paramount PB-100 does not include apressure ring for increasing the efficiency of the impeller in theblower mode.

The present system offers an alternate convertible blower/vac. Inparticular, the present invention includes a convertible electricblower/vac with an improved air inlet cover and adjustable choke member.The present invention also includes an improved system for attaching ablower tube and a vacuum bag assembly to the housing outlet of theblower/vac housing. The present invention also includes an improvedvacuum tube for use of the blower/vac in the vacuum mode. The presentinvention also includes means for reducing unwanted rotationaldeflection of the blower tube when it is engaged on the housing outlet.

SUMMARY OF THE INVENTION

Accordingly, the present invention includes an improved convertibleelectric blower/vac.

Specifically, this invention includes an improved air inlet cover andadjustable choke member wherein the air inlet cover includes a pressurering for increasing the efficiency of the blower/vac impeller in theblower mode. The choke member of the air inlet cover could also includean extended choke lever for ease of adjusting the choke member.

This invention can also include an improved blower tube including animproved means for connecting the blower tube to the housing outlet. Theblower tube can include a series of longitudinal ribs extending alongthe internal surface of the blower tube from the upstream end toward thedownstream end wherein the ribs engage the housing outlet when theblower tube is engaged over the housing outlet. The blower tube caninclude an improved downstream end for increasing the exiting airvelocity.

This invention can also include an improved housing outlet for engagingand retaining the blower tube when it is engaged on the housing outlet.

This invention can also include an improved vacuum bag collar forconnecting a vacuum bag to the blower/vac wherein the vacuum bag collarincludes means for connecting the vacuum bag collar to the housingoutlet. The vacuum bag collar can include a series of longitudinal ribsextending along the internal surface of the vacuum bag collar from theupstream end toward the downstream end wherein the ribs engage thehousing outlet when the vacuum bag collar is engaged over the housingoutlet.

The air inlet cover of the present invention can also include aplurality of quarter-spherical indentations each adapted to receive afingertip so as to permit the air inlet cover to be grasped and rotatedwith ease when engaging the air inlet cover over the air inlet openingof the housing.

This invention can also include an improved vacuum tube for use with theblower/vac in the vacuum mode.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention will be further described with reference to the appendedDrawing, wherein:

FIG. 1 is an exploded view of a preferred embodiment convertibleelectric blower/vac set up for operation in the vacuum mode.

FIG. 2 is an exploded view of the housing, motor and impeller assemblyof the preferred blower/vac.

FIG. 3 is a left side elevational view of the preferred housingassembly.

FIG. 4 is an exploded view of the preferred housing assembly includingthe preferred air inlet cover assembly.

FIG. 5 is a front elevational view of the right half of the housing ofthe preferred blower/vac.

FIG. 6 is a bottom plan view of the impeller of the preferredblower/vac.

FIG. 7 is a side elevational view of the air inlet cover of thepreferred blower/vac.

FIG. 8 is a bottom plan view of the air inlet cover of the preferredblower/vac.

FIG. 9 is a top plan view of the air inlet cover of the preferredblower/vac.

FIG. 10 is a perspective view of the adjustable choke member of thepreferred blower/vac.

FIG. 11 is a side elevational view of the adjustable choke member of thepreferred blower/vac.

FIG. 12 is a top plan view of the adjustable choke member of thepreferred blower/vac.

FIG. 13 is a bottom plan view of the left half of the housing of thepreferred blower/vac.

FIG. 14 is a perspective view of the lower portion of the vacuum tubeassembly of the preferred blower/vac.

FIG. 15 is a perspective view of the upper portion of the vacuum tubeassembly of the preferred blower/vac.

FIG. 16 is a second perspective view of the upper portion of the vacuumtube assembly of the preferred blower/vac.

FIG. 17 is a top plan view of the upper portion of the vacuum tube ofthe vacuum tube assembly of the preferred blower/vac.

FIG. 18 is a second perspective view of the lower portion of the vacuumtube assembly of the preferred blower/vac.

FIG. 19 is a top plan view of the lower portion of the vacuum tubeassembly of the preferred blower/vac.

FIG. 20 is a perspective view of the vacuum bag collar of the preferredblower/vac.

FIG. 21 is a side elevational view of the vacuum bag collar of thepreferred blower/vac.

FIG. 22 is a rear elevational view of the vacuum bag collar of thepreferred blower/vac.

FIG. 23 is a top plan view of the vacuum bag collar of the preferredblower/vac.

FIG. 24 is an exploded view of the preferred blower/vac with the blowertube.

FIG. 25 is a perspective view of the blower tube of the preferredblower/vac.

FIG. 26 is a sectional view taken along line 26--26 of FIG. 25 of theblower tube of the preferred blower/vac.

FIG. 27 is a partial side elevational view of the blower tube of thepreferred blower/vac.

FIG. 28 is a rear end view of the blower tube of the preferredblower/vac.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

In the description which follows, like parts are indicated throughoutthe specification with the same reference numerals, respectively.

FIGS. 1 and 2 show an electric blower/vac 1. The blower/vac 1 includes ahousing 2 that is constructed of a plastic material such as ABS. Aprimary handle 4 is located at the top of the housing 2. A generallycylindrical primary handle extension 16 is located at the front of theprimary handle 4 and has a longitudinal axis that runs perpendicularlyto the longitudinal axis of the primary handle 4. The housing 2 includesan air inlet opening 64 and a housing outlet 28 which includes an outletorifice 18. The air inlet opening 64 resides in a first plane while theoutlet orifice 18 lies in a second plane that is substantiallyperpendicular to the first plane. An electric motor 17 is mounted withinthe housing 2. A motor output shaft 29 extends downwardly from the motor17. The motor output shaft 29 runs in a direction that is generallyperpendicular to the plane that the air inlet opening 64 lies in. Animpeller 39 is attached to the output shaft 29 of the electric motor 17and is secured with a washer 62 and a nut 63 as shown in FIG. 4.

Electrical energy is selectively supplied to the electric motor 17 asfollows. A male electrical cord connector 33 is adapted for mountingbetween the halves of the housing 2 so that it protrudes outwardly fromthe housing 2 when it is assembled. The connector 33 can be connected toan extension cord (not shown) that delivers electricity from a femaleelectrical outlet (not shown). Electrical wires 32 and 34 carry thecurrent from the connector 33. An electrical switch 35 is wired inseries with the motor 17 and connector 33 and opens and closes theelectrical circuit for the motor. An actuator 37 mounts directly overswitch 35 such that movement of actuator 37 from one side to the othercauses switch 35 to move from an open circuit position to a closedcircuit position or vice versa. A safety interlock switch 38 isconnected in series to the motor 17 and switch 35 by wires 30a and 34a.Safety interlock switch 38 and its function will be discussed in moredetail below.

An air inlet cover 66 is adapted to be removably engaged over the airinlet opening 64. The air inlet cover is shown in detail in FIGS. 4, 7,8 and 9. Air inlet cover 66 is designed to permit air to be drawn intothe housing 2 when the impeller 39 is rotated by the motor 17. Air inletcover also acts as a guard over the impeller to prevent the operatorfrom contacting the rotating impeller 39. The air inlet cover 66 alsoincludes an actuating system, which will be discussed in more detailbelow, that closes the contacts of the safety interlock switch 38 whenthe cover 66 is properly engaged over the air inlet opening 64 and whichopens the safety interlock switch when the cover 66 is removed from theair inlet opening 64. The air inlet cover 66 also includes a means forincreasing the efficiency of the blower/vac when it is operated in theblower mode. Finally, the air inlet cover 66 includes a means foradjusting the air inlet area through the cover 66. All of these featureswill now be discussed in more detail.

The air inlet cover 66 includes a series of spokes and openings definingan air grate. The air grate allows the passage of air through the cover66 while at the same time providing a barrier for passage of objectsthat could come into contact with the rotating impeller 39. A series ofradially disposed grate spokes 100 extend radially away from a hubopening 95 located at the center of the air inlet cover 66. The radiallydisposed grate spokes 100 define a series of radially disposed grateorifices 96 that are interposed between the radially disposed gratespokes 100. A series of vertically or axially disposed grate spokes 83extend generally perpendicularly up, as viewed in FIG. 4, and away fromthe radially disposed grate spokes 100. The vertically disposed gratespokes 83, in the preferred embodiment, are actually extensions of theradially disposed grate spokes 100 since the air inlet cover 66 is anintegrally molded plastic component. The vertically disposed gratespokes 83 define a series of vertically disposed grate orifices 84 thatare interposed between the vertically disposed grate spokes 83. Thevertically disposed grate spokes 83 terminate at their uppermost ends bysupporting a pressure ring 67. The pressure ring 67 is designed toincrease the efficiency of the impeller 39 when the air inlet cover 66is engaged over the air inlet opening 64. When the air inlet cover 66 isengaged over the air inlet opening 64, the pressure ring 67 ispositioned immediately adjacent to the impeller 39. When the impeller 39is rotating, it draws air in through the air grate and expels it throughthe outlet orifice 18 of the housing outlet 28. The pressure ring 67reduces the amount of air that leaks or spills over from the highpressure side of the impeller 39 blades. By reducing the spillover ofair, the efficiency of the impeller 39 is increased. That is, the outputair horsepower of the impeller 39 is increased for a given motor output(shaft) horsepower. Without the pressure ring 67, the impeller 39 wouldspill more air axially rather than discharging it radially as isdesirable.

An adjustable choke member 105 is adapted to "snap-fit" over the airinlet cover 66. The adjustable choke member 105 is shown in FIGS. 4, 10,11 and 12. Adjustable choke member 105 includes a hub region 107 and aperimeter region 108. A total of four clips 104 extend perpendicularlyfrom the hub region 107 as shown in FIG. 11. The clips 104 includeraised portions 106 at the ends of the clips 104 furthest from the hub107. The four clips 104 are spaced angularly apart from one another by90 degrees. The clips 104 are also spaced radially from the center ofthe hub 107 such that the clips 104 can be inserted into the hub opening95 of air inlet cover 66, thus axially restraining the choke member 105onto the air inlet cover 66. The raised portions 106 of the clips 104retain the choke member 105 axially as the raised portions "hook" theinside of the hub opening 95 along bearing surface 103 of air inletcover 66 (FIG. 9.).

A choke lever 102 extends radially out from the choke member 105 asshown in FIGS. 4, 10, 11 and 12. When the choke member 105 is secured bya "snap fit" onto the air inlet cover 66 as described above, the chokelever 102 nests within the choke lever opening 101. The choke leveropening 101 is sized such that the choke lever 102 can move back andforth between the walls 94 of the choke lever opening 101 as shown inFIG. 8. This back and forth movement permits the choke member 105 to bepivotally rotated about the hub opening 95 of the air inlet cover 66.The total pivotal movement of the choke member 105 allowed by thepreferred embodiment is approximately 5 to 10 degrees, since the walls94 act as stops for the choke lever 102.

The choke member 105 includes a series of radially disposed choke spokes99 extending between the choke hub region 107 and the perimeter region108. A series of radially disposed choke orifices 98 extend between thechoke hub region 107 and the perimeter region 108 and are interposedbetween the radially disposed choke spokes 99. A series of verticallydisposed choke spokes 97 extend generally perpendicularly up, as viewedin FIG. 4, and away from the radially disposed choke spokes 99. Thevertically disposed choke spokes 97 are, in the preferred embodiment,actually extensions of the radially disposed choke spokes 99 since thechoke member 105 is an integrally molded element. The verticallydisposed choke spokes 97 define a series of vertically disposed chokeorifices 93 that are interspersed with the vertically disposed chokespokes 97.

The choke member 105 has an inner diameter 92 that is just slightlylarger than the outer diameter 91 of the air grate portion of the airinlet cover 66. In the preferred embodiment, the inner diameter 92 andthe outer diameter 91 both decrease slightly from the uppermost tolowermost points of the air inlet cover 66 and the choke member 105.This slight decrease in the diameters is provided as draft for gettingthe molded component out of the manufacturing mold. The slightdifference between the diameters of the components permits a close fitbetween the choke member 105 and the grate portion of the air inletcover 66 which, in turn, permits a tighter air seal between the chokemember 105 and the grate portion of the cover 66 and, thus, bettercontrol over the air flow through the air inlet cover 66. The chokemember 105 has a height 88 (see FIG. 11) such that, when the chokemember 105 is secured onto the air inlet cover 66, the verticallydisposed choke spokes 97 and vertically disposed choke orifices 93 aregenerally equal in length to the vertically disposed grate spokes 83 andthe vertically disposed grate orifices 84. Also, the height 88 of thechoke member is such that radially disposed choke spokes 99 and theradially disposed choke orifices 98 closely overlie the radiallydisposed grate spokes 100 and the radially disposed grate orifices 96.This relatively tight fit of the choke member 105 and its spokes andorifices in relation to the spokes and orifices of the grate providesfor a relatively tight air seal when the orifices of the grate areclosed off and also provides for a more controllable air adjustmentsystem.

The choke member 105, as discussed above, is adapted to "snap fit" ontothe air inlet cover 66. Once the choke member 105 is secured onto theair inlet cover 66, the choke member 105 can be pivoted back and forthabout the hub opening 105 of the cover 66. When the choke member 105 ispivoted selectively in a first direction, the radially disposed chokespokes 99 obstruct the radially disposed grate orifices 96, and thevertically disposed choke spokes 97 obstruct the vertically disposedgrate orifices 84. In this first position with the grate orificesgenerally obstructed by the choke spokes, the air inlet area of the airinlet cover 66 is greatly reduced. At least a small amount of air canpass through the clearance spaces between the choke member 105 and thegrate of the air inlet cover 66 since there is no air tight seal betweenthe choke member 105 and the air grate, even with the choke member 105in the first position. That is, the air choke 105 and the air grate ofthe air inlet cover 66 do not fit together so tightly that they prohibitthe passage of air through the air inlet cover 66 when the choke member105 is in its first position.

When the choke member 105 is pivoted in a second direction opposite tothe first direction, the radially disposed choke spokes 99 move awayfrom the radially disposed grate orifices 96, thus exposing the radiallydisposed grate orifices 96 for passage of air through the air inletcover 66. Also, the movement of the choke member 105 in a seconddirection opposite to the first direction moves the vertically disposedchoke spokes 97 away from the vertically disposed grate orifices 84,thus exposing the vertically disposed grate orifices 84 for passage ofair through the air inlet cover 66. With the choke member 105 in itssecond position, the air intake area of the grate of the air inlet cover66 is opened to its maximum. Thus, in this position, the airflow throughthe blower/vac 1 is maximized. A detent protrusion 90 is located in thechoke lever opening 101 at a point approximately midpoint between thechoke lever opening walls 94. Mating detent cavities 89 located on theupper side of the choke lever 102, as shown in FIGS. 4 and 12, interactwith the detent protrusion 90 such that the choke member 105 is held inthe first or second position and can only be moved out of position by amoderate amount of force. That is, the detent protrusion 90 and thedetent cavities 89 interact to prevent inadvertent movement of the chokelever 102 and the choke member 105 from its set position relative to airinlet cover 66.

The air inlet cover 66 also includes means for removably engaging thecover 66 over the air inlet opening 64. Male engagement members 20 and21 are located approximately 180 degrees apart from one another on theperimeter of the air inlet cover 66. As can be seen in FIGS. 7 and 9,the two male engagement members 20 and 21 are different from oneanother. Matching slots 22 and 23 in the housing 2 of the blower/vac arepositioned at the air inlet opening 64 and are best shown in FIGS. 2 and13. Slot 23 is sized so as to accept only male engagement member 21.Slot 22 is sized so as to accept only male engagement member 20. Thus,the air inlet cover 66 can only be engaged over the air inlet opening 64in one orientation. In the preferred embodiment, the air inlet cover 66is engaged over the air inlet opening 64 such that the choke lever 102and the choke lever opening 101 are positioned at the left side (whenviewed from the operator looking down) of the air inlet cover 66.

The safety interlock switch 38 is mounted in the housing 2 within acavity 40 that is located at the rear of the air inlet opening 64. Thecavity 40 is positioned just behind slot 23. The safety interlock switchincludes an actuator 41 that protrudes out of the cavity 40 and into thearea immediately adjacent to the slot 23. When the air inlet cover 66 isengaged over the air inlet opening 64, the male engagement member 21engages and depresses the actuator 41 and closes the contacts in theswitch 38. When the air inlet cover 66 is removed from over the airinlet opening 64, the male engagement member 21 moves away from theactuator 41, allowing the actuator 41 to extend back out from itsdepressed position. When the actuator 41 is again extended, the contactsof the safety interlock switch 38 are opened. The safety interlockswitch 38 is connected in series to the electrical on-off switch 35. Theelectric blower/vac motor 17 cannot be energized unless the contacts ofthe safety switch 38 are closed and the contacts of the electricalon-off switch 35 are closed. Thus, if the contacts of the interlockswitch 38 are open when the air inlet cover 66 is removed, the motor 17cannot be energized even if the contacts of the on-off electrical switch35 are closed.

The air inlet cover 66 also includes a series of quarter sphericalindentations 10 spaced around the lower perimeter of the cover 66. Inthe preferred embodiment, a total of 11 quarter spherical indentationsare spaced evenly around the lower perimeter of the air inlet cover 66.This is best shown in FIGS. 7 and 8. The quarter spherical indentations10 are designed to comfortably accommodate the operator's fingers whengrasping the air inlet cover 66 to engage it over the air inlet 64 orwhen removing it from the air inlet 64.

The air inlet cover 66 is retained over the air inlet opening 64 asfollows. The air inlet cover 66 is aligned with the slots 22 and 23 sothat the male engagement members 20 and 21 are aligned with the matchingslots. Then the air inlet cover 66 is pushed onto the air inlet opening64 so that the engagement members 20 and 21 pass through thecorresponding slots 22 and 23. When the male engagement members 20 and21 have cleared the slots 22 and 23, the air inlet cover 66 can then berotated in a clockwise (looking at the cover from the bottom of theblower/vac) direction until a detent locking system (not shown)rotationally retains the air inlet cover 66. The locking force exertedby the detent system keeps the air inlet cover 66 from unwanted rotationbut can be overcome by a moderate amount of force exerted by theoperator. Thus, when the operator chooses to remove the air inlet cover66, he simply needs to grasp the quarter spherical indentations 10 androtate the air inlet cover 66 counter-clockwise until the detentretention force is overcome. Once the detent retention force isovercome, the air inlet cover 66 can be further rotated until the maleengagement members 20 and 21 are aligned with the slots 22 and 23. Atthat point, the air inlet cover 66 can simply be lifted axially awayfrom the air inlet opening 64 and removed from the housing 2.

The electric blower/vac 1 includes a detachable discharge nozzle orblower tube 44. The blower tube 44 is configured so as to be detachablymountable onto the housing outlet 28. The blower tube 44 includes a setof resilient tabs 45 that extend from the upstream end of the tube 44.The tabs are positioned 180 degrees apart from each other so that one ofthe tabs 45 is situated at the top surface of the tube 44 while theother is situated at the bottom surface of the tube 44. This is bestshown in FIGS. 24 and 27. Each tab 45 includes a lip 46 located at thefar upstream end of each tab 45. The tabs 45 interact with matingreceptacles 47 located on the perimeter of the housing outlet 28. Thereceptacles 47 are best shown in FIGS. 1, 2, 3, 4, 5 and 24. As bestseen in FIGS. 3 and 5, each receptacle 47 is formed by first and secondsidewalls 48 and a top surface 49. A slot 50 is formed in the topsurface 49 of each receptacle 47. The resilient tabs 45 on the blowertube 44 are suitably dimensioned to fit within the receptacles 47. Whenthe resilient tabs 45 of the blower tube 44 are inserted into thereceptacles 47, the lips 46 of the tabs 45 engage the slots 50 of thereceptacles 47, thus retaining the blower tube 44 onto the housingoutlet 28. To release the blower tube 44 from the housing outlet 28, theresilient tabs 45 are simply depressed which removes the lips 46 fromthe slots 50 and which allows the tabs 45 and the tube 44 to be pulledaway from the housing outlet.

The upstream end of the blower tube 44 has an opening 51 with across-section that is substantially identical to the cross-section ofthe housing outlet 28. The cross-section of the upstream opening 51 ofthe tube 44 is best shown in FIG. 28. This cross-sectional area, as wellas the cross-sectional area of the housing outlet orifice 18, can bestbe described as two substantially parallel lines joined by twosemi-circles. The inside of the upstream end of the blower tube 44 isdimensioned so that it fits snugly over the outside surface of thehousing outlet 28. As described above, the resilient tabs 45 and matingreceptacles 47 interact to secure the blower tube 44 onto the housingoutlet 28 when the tube 44 is pushed onto the outlet 28. A flange 53acts as a stop for the upstream end of the blower tube 44 as it ispushed onto the housing outlet 28.

A series of ribs 52 run longitudinally along the inner surface of theupstream end of the blower tube 44. The ribs 52 can be seen best inFIGS. 27 and 28. The ribs begin at the upstream opening 51 and thenextend in a downstream direction to a smooth, continuous raised portion54 that extends around the entire inner perimeter of the blower tube.The location of the raised portion is shown in FIG. 27. The raisedportion 54 has a longitudinal axis that runs perpendicularly to thelongitudinal axis of each rib 52. The longitudinal axis of the raisedportion 54 is located approximately 2 inches from the upstream end ofthe blower tube 44. The raised portion 54 acts as an air seal betweenthe housing outlet 28 and the blower tube 44 when the blower tube 44 isattached to the outlet 28. Thus, the ribs 52 act as guides for guidingthe blower tube onto the housing outlet 28 while the raised portion 54,which is the last portion of the blower tube 44 that encounters thehousing outlet 28 when the tube 44 is inserted onto the outlet 28, actsas an air seal between the two components. The ribs 52 not only guidethe tube onto the outlet 28, they reduce the amount of force required toguide the tube 44 onto the outlet 28 compared to a full length, fullcontact surface. Also, the ribs 52 and the housing outlet 28 combine toreduce the detrimental effect caused by debris caught between the blowertube 44 and the housing outlet 28. Furthermore, a set of guides 27located on the housing outlet 28 and as shown in FIGS. 3, 4, and 5,coact with the longitudinal ribs 52 to aid in guiding the blower tube 44onto the housing outlet 28. The guides 27 are located 180 degrees apartfrom each other as seen in FIGS. 3 through 5. The guides 27 alsocooperate with the longitudinal ribs 52 to reduce unwanted rotation ofthe blower tube 44 once it is fully attached to the housing outlet 28.In the preferred embodiment, only one rib 52 engages either guide 27.

The blower tube 44 tapers from its upstream opening 51 to its downstreamopening 55. The downstream opening 55 is shown best in FIGS. 24, 25 and28. The downstream opening 55 has a generally ellipsoidal cross-section.In the preferred embodiment, the downstream opening 55 has across-sectional area that is approximately 25% of the cross-sectionalarea of the upstream opening 51. As shown in FIGS. 24 and 25, thereduction in cross-sectional area between the upstream opening 51 andthe downstream opening 55 occurs gradually since the blower tube tapersfrom the upstream end to the downstream end. The reduction incross-sectional area through the tube 44 causes the air to increase invelocity as it travels down the tube 44 into the smaller cross-sectionalareas. The result is a high velocity stream of air discharged from thedownstream opening 55 when the blower/vac is operated in the blowermode.

A vacuum bag collar 70 is shown in FIGS. 1, 20, 21, 22 and 23. Collar 70is adapted to snap-fit onto housing outlet 28 and includes resilienttabs 71 that extend in an upstream direction from the upstream end ofthe collar 70. The resilient tabs 71 each include a lip 72 at the farupstream end of each tab 71. The lips 71 are configured so as to engagethe slots 50 in the receptacles 47 located on the housing outlet 28.When the lips 72 engage the slots 50 of the receptacles 47, the collar70 is retained on the housing outlet 28.

Collar 70 also includes a series of ribs 73 that run longitudinallyalong the inner upstream surface of the collar 73. The ribs 73 can beseen best in FIGS. 20, 21 and 22. The ribs 73 begin at the upstream endof the collar 70 and extend in a downstream direction to a smooth,continuous raised portion 74 that extends around the entire innerperimeter of the collar 70. The raised portion 74 has a longitudinalaxis that runs perpendicularly to the longitudinal axis of each rib 73.The longitudinal axis of the raised portion 74 is located approximately2 inches from the upstream end of the vacuum bag collar 70. The raisedportion 74 acts as an air seal between the housing outlet 28 and thecollar 70 while the ribs 73 act as guides for guiding the collar 70 ontothe housing outlet 28. The ribs 73 also reduce the amount of forcerequired to guide the collar 70 onto the housing outlet 28. The collar70 also includes a flange 75 that extends around the outer surface ofthe collar 70. The longitudinal ribs 73 on the vacuum bag collar 70 alsointeract with the guides 27 on the housing outlet 28, in the same mannerthat the ribs 52 on the blower tube 44 interact with the guides 27, toreduce unwanted rotation of the vacuum bag collar 70 once it is fullyengaged on the housing outlet 28.

A vacuum bag 76 includes an opening 77 that has a Velcro strap 78extending around the perimeter of the opening 77. The bag 76 alsoincludes a shoulder strap 79 that extends from the top of the bag 76 toform a loop. The looped shoulder strap 79 is adapted to fit over theoperator's shoulder when the blower/vac is operated in the vacuum mode.The strap 79 has adjustment means 80 for lengthening or shortening thestrap 79. The opening 77 of the bag 76 is sized so that it fits over theflange 75 of the collar 70. Once the bag opening 77 has cleared theflange 75, the Velcro strap 78 can be adjusted so that the bag opening77 is tightened around the collar 70, thus retaining the bag 76 onto thecollar 70. The bag 76 is constructed of a somewhat porous fabric thatpermits the passage of air exhausted from the blower/vac but retains thedebris collected while vacuuming. The bag 76 also includes a zipper 81located at the bottom of the bag 76 for emptying debris.

A vacuum tube assembly 5 is shown in FIG. 1. To operate the blower/vacin the vacuum mode, the vacuum tube assembly 5 must be connected to theair inlet opening 64 and the vacuum bag 76 and collar 70 must beconnected to the housing outlet 28. The blower tube assembly 5 includesan upper vacuum tube 6 and a lower vacuum tube 7. The upper vacuum tubeincludes a secondary handle 8 that provides a secondary gripping surfacefor the operator when the unit is operated in the vacuum mode. Thesecondary handle 8 also provides a gripping surface that will aide theoperator in maneuvering the upper vacuum tube 6 to connect it to thehousing 2. The upper vacuum tube 6 has a generally cylindricalcross-section throughout its entire length. This cross-section can bestbe seen in FIGS. 1, 15 and 17. The upper vacuum tube 6 also has a set ofmale engagement members 9 and 11 located at the upper end of the tube asshown in FIGS. 1, 15 and 17. The male engagement members 9 and 11 aresized and positioned to engage the slots 22 and 23 on the housing in thesame manner as the engagement members 20 and 21 of the air inlet cover66 engage the slots 22 and 23. The male engagement member 11 alsocontacts and depresses the actuator 41 on the safety interlock switch 38when the vacuum tube 6 is fully engaged over the air inlet 64. Thecontacts of the safety interlock switch 38 are thus closed. Thus, themale engagement members 9 and 11 interact with the slots 22 and 23 toform a means for connecting and disconnecting the vacuum tube 6 over theair inlet opening 64 of the housing 2.

The lower vacuum tube 7 is best shown in FIGS. 1, 14, 18 and 19. The topof the lower vacuum tube 7 is circular in cross-section and has an innerdiameter that is slightly larger than the outer diameter of the lowerend of the upper vacuum tube 6. Thus, the lower tube 7 is connected tothe upper tube 6 by means of a frictional fit between the two tubes, thefrictional fit created by the dimensional interference between thetubes. The lower tube's cross-section changes from substantiallycircular at its top end to a substantially ellipsoidal cross-section atits lower end. The ellipsoidal cross-section is best shown in FIG. 19.The change in cross-section is gradual from one end of the tube to theother. In the preferred embodiment, the circular cross-section runs fromthe top of the tube in a downward direction for approximately 21/4inches. This extended cylindrical section 12 is shown in FIGS. 14 and18. At the lower end of the cylindrical section 12, the transition fromcylindrical to ellipsoidal cross-section begins and continues on downthe lower end of the tube 7 until the ellipsoidal cross-section is fullydeveloped.

Operation of the blower/vac is as follows. First, to operate theelectric blower/vac in the blower mode, the operator should attach theblower tube 44 to the housing outlet 28 by sliding the tube 44 onto thehousing outlet 28 until the lips 46 of the resilient tabs 45 engage theslots 50 of the receptacles 47. Then, the air inlet cover 66 must beengaged over the air inlet opening 64. To do this, the operator alignsthe male engagement members 20 and 21 on the air inlet cover 66 with thecorresponding slots 22 and 23 adjacent to the air inlet opening 64. Thenthe operator pushes the members 20 and 21 through the slots 22 and 23.Once the members 20 and 21 pass through the slots 22 and 23, the cover66 is rotated clockwise (looking at the bottom of the housing) until thesafety interlock switch 38 contacts are closed and the detent systemengages the cover 66 to prevent unwanted rotation of the cover 66. Theoperator must also connect an extension cord to the male electrical cordconnector. An electrical supply commensurate with the design of themotor is required. For example, a standard U.S. model blower/vac wouldrequire 120 volt-60 HZ alternating current while a European model wouldrequire 230 volt-50 HZ alternating current. Once the electrical supplycord is attached, the operator can energize the motor 17 by turning theswitch 35 on with the actuator 37. The motor 17 rotates the impeller 39at about 16,000 rpm in the preferred embodiment. The impeller 39 drawsair up through the air grate of the air inlet cover 66. The pressurering 67, which is positioned adjacent to the impeller 39 when the cover66 is engaged over the inlet opening 64, reduces axial spillover off ofthe impeller blades, thus improving the impeller's efficiency. Air isexpelled through the housing outlet 28 and the blower tube 44. As theair travels through the blower tube 44, the cross-sectional area of thetube 44 decreases and the velocity of the air stream increases. Thevelocity of the air stream is at its maximum when it passes through thedownstream opening 55 of the tube. The operator typically holds theblower/vac by its primary handle 4 with one hand when using it in theblower mode. The downstream opening 55 and the exiting airstream isaimed at the debris to be moved. Airflow through the blower/vac can beadjusted by moving the choke member 105 as described above. Maximumairflow is desirable for use in moving heavier debris such as dampleaves while a lower airflow setting might be used when blowing lighterdebris out of a garage.

To operate the blower/vac in the vacuum mode, the operator must turn offthe switch 35 with the actuator 37 and remove the power supply cord fromthe cord connector 33. The blower tube 44 can be removed by depressingthe resilient tabs 45 at the upstream end of the tube 44 and by pullingthe tube 44 away from the housing outlet 28. The air inlet cover 66 mustbe removed by first rotating it in a counterclockwise direction (lookingat it from the bottom) and then pulling it away from the air inletopening 64. At this point, the upper vacuum tube 6 should be installedover the air inlet opening 64. The male engagement members 9 and 11 onthe vacuum tube 6 must be aligned with the slots 22 and 23 near the airinlet opening 64. The vacuum tube 6 should be pushed towards the airinlet opening 64 so that the engagement members 9 and 11 pass throughthe slots 22 and 23. The operator can then rotate the vacuum tube 6 in aclockwise direction (bottom view) to lock it into place by grasping thesecondary handle 8 and rotating the vacuum tube 6 as required. The lowervacuum tube 7 is then attached to the upper vacuum tube 6 by africtional fit as described above. The vacuum bag 76 and vacuum bagcollar 70 must next be attached to the housing outlet 28. The vacuum bag76 and collar 70 might come assembled from the factory. If not, the bag76 must be attached to the collar 70 by the operator in the mannerdescribed above. The collar 70 and bag 76 assembly can then be attachedto the housing outlet 28 by aligning the resilient tabs 71 on the collar70 with the receptacles 47 on the housing outlet and by pushing thecollar 70 toward the outlet 28 until the tabs 71 snap into place withinthe receptacles 47. The bag 76 should be oriented as shown in FIG. 1with the zipper 81 facing in a downward direction while the shoulderstrap 79 is oriented in an upward direction. The operator can thenattach the electrical supply cord to the cord connector 33 and turn theswitch 35 to the on or run position.

Once the motor 17 is electrically energized, the operator can maneuverthe blower/vac in the vacuum mode as follows. The operator can place theshoulder strap 79 of the vacuum bag over one shoulder. The operator canplace one hand on the primary handle 4 and the other hand on thesecondary handle 8. For ease of operation, the secondary handle 8 shouldbe pointed in a forward direction while the operator is handling theblower/vac in the vacuum mode. That is, the primary handle 4 will becloser to the operator than the secondary handle 8 is during operationof the blower/vac in the vacuum mode. The vacuum tube assembly 5 will,of course, be directed in a downwardly extending direction while theunit is operated in the vacuum mode. Debris such as leaves can bevacuumed up through the vacuum tube assembly 5. The impeller 39 drawsair and debris up through the vacuum tube assembly 5 and through theimpeller 39. As debris passes through the impeller 39, it is chopped andreduced in volume. The air and debris is then exhausted through thehousing outlet 28 and into the vacuum bag 76. The vacuum bag 76 issomewhat porous so that the exhaust air can pass through the bag 76while the debris is retained by the bag 76. When the vacuum bag 76 fillswith debris, the operator can proceed to empty it by turning the motor17 off and by disconnecting the bag 76 and collar 70 from the housingoutlet 28. The operator can then empty the bag 76 through the openedzipper 81. The bag can be emptied into a compost pile or into a suitablecontainer for disposing of the debris. In the preferred embodiment,there is no means for adjusting the air speed of the blower/vac in thevacuum mode. The higher speed is desirable in the vacuum mode as itreduces the chances of debris clogging.

It should be noted that the preferred design of the vacuum tube assembly5 provides an improved system for vacuuming debris. As described above,the lower end of the lower vacuum tube 7 includes a generallyellipsoidal cross-sectional area. The ellipsoidal opening at the lowerend of the lower vacuum tube 7 has a larger cross-sectional area thanthe upper end of the lower tube 7 which has a circular cross-sectionalarea. The larger cross-sectional area at the bottom of the tube 7reduces the likelihood of bridging of debris across the opening. Thegradual taper to a smaller, circular cross-sectional area at the top ofthe lower tube 7 causes the incoming air and debris to accelerate as itmoves upwardly through the lower tube 7. The upper tube 6 has a circularcross-sectional area throughout its entire length.

Also, in the vacuum mode, the blower/vac does not have the air inletcover 66 attached over the air inlet opening 64. Thus, the pressure ring67 is not in place near the impeller 39 when the unit is operated in thevacuum mode. While the overall air moving efficiency of the impeller 39is reduced when the pressure ring 67 is not in place, the impeller 39 isless likely to clog with debris since the air inlet opening 64 isunrestricted. Thus, the debris handling capability of the impeller 39 isenhanced with the increased air inlet opening area available after theair inlet cover 66 and its pressure ring 67 are removed.

To convert the blower/vac from operation in the vacuum mode to operationin the blower mode, the operator must turn off the switch 35 and unplugthe power supply cord from the electrical cord connector 33. Theoperator can then disconnect the vacuum bag 76 and vacuum bag collar 70from the housing outlet 28 by depressing the resilient tabs 71 andpulling the collar and bag assembly axially away from the housing outlet28. Next, the operator must remove the vacuum tube assembly 5 from theair inlet opening 64. This can be accomplished by grasping the secondaryhandle and rotating the vacuum tube assembly 5 until the engagementmembers 9 and 11 can pass through the slots 22 and 23. At that point,the vacuum tube assembly 5 can be pulled away from the air inlet opening64. The blower/vac unit is now ready to be assembled back into theblower mode as described above.

A preferred embodiment of the invention is described above. Thoseskilled in the art will recognize that many embodiments are possiblewithin the scope of the invention. Variations and modifications of thevarious parts and assemblies can certainly be made and still fall withinthe scope of the invention. Thus, the invention is limited only to theapparatus recited in the following claims, and equivalents thereof.

We claim:
 1. A convertible electric blower/vacuum comprising:(a) ahousing, the housing including an air inlet opening and a housingoutlet; (b) a blower tube comprising:(i) an upstream end removablyengageable with the housing outlet; (ii) a downstream end; and (iii) aplurality of longitudinal ribs extending along an internal surface ofthe blower tube from the upstream end toward the downstream end whereinthe ribs engage the housing outlet when the blower tube is engaged overthe housing outlet.
 2. The convertible blower vacuum of claim 1, whereinthe ribs extending from the upstream end of the blower tube toward thedownstream end of the tube terminate at a smooth, raised portionextending around an inner perimeter of the blower tube, the smooth,raised portion also engaging the housing outlet when the blower tube isengaged over the housing outlet.
 3. The convertible blower vacuum ofclaim 2, wherein the smooth, raised portion has a longitudinal axisrunning perpendicularly to the longitudinal axis of each rib.
 4. Theconvertible blower vacuum of claim 3, wherein the longitudinal axis ofthe smooth, raised portion is between 1.75 and 2.25 inches from theupstream end of the blower tube.
 5. The convertible blower/vac of claim4, wherein the housing outlet comprises a guide for interacting with thelongitudinal ribs of the blower tube to reduce rotational movement ofthe blower tube when the blower tube is engaged on the housing outlet.6. A convertible electric blower/vacuum comprising:(a) a housing, thehousing including an air inlet opening and a housing outlet; (b) avacuum bag collar comprising:(i) an upstream end removably engageablewith the housing outlet; (ii) a downstream end; and (iii) a plurality oflongitudinal ribs extending along an internal surface of the vacuum bagcollar from the upstream end toward the downstream end wherein the ribsengage the housing outlet when the vacuum bag collar is engaged over thehousing outlet.
 7. The convertible blower/vacuum of claim 6, wherein theribs extend from the upstream end of the vacuum bag collar toward thedownstream end of the collar and terminate at a smooth, raised portionextending around an inner perimeter of the collar, the smooth, raisedportion also engaging the housing outlet when the vacuum bag collar isengaged over the housing outlet.
 8. The convertible blower/vacuum ofclaim 7, wherein the smooth, raised portion has a longitudinal axiswhich runs perpendicular to the longitudinal axis of each rib.
 9. Theconvertible blower/vacuum of claim 8, wherein the longitudinal axis ofthe smooth, raised portion is between 1.75 and 2.25 inches from theupstream end of the vacuum bag collar.
 10. The convertible blower/vac ofclaim 7, wherein the housing outlet comprises a guide for interactingwith the longitudinal ribs of the vacuum bag collar to reduce rotationalmovement of the vacuum bag collar when the vacuum bag collar is engagedon the housing outlet.